1. Field of the Invention
This invention rebates to a novel and useful ester compound having the structure of an ester between a quinolonecarboxylic acid and a steroid compound, a method for its production, and the use of the compound. More particularly, this invention relates to a compound having the structure of an ester between the carboxyl group of a quinolonecarboxylic acid and the alcoholic hydroxyl group in 21-position of asteroid compound or a pharmacologically acceptable salt thereof, to a method for the production of said compound and salt, and to an antibacterial composition and an antiinflammatory composition each comprising said compound or salt as an active ingredient.
2. Description of the Prior Art
In bacterial infections, the first therapeutic aim is to exterminate the bacteria with an antibiotic or antibacterial agent. While the antibiotics heretofore available are only sparingly active against MRSA (meticillin-resistant Staphylococcus aureus), synthetic antibacterial agents, typically quinolonecarboxylic acid, are considered promising and under intensive research. Meanwhile, bacterial infections are accompanied by inflammations in many clinical cases and, therefore, the concomitant administration of either a nonsteroidal or a steroidal antiinflammatory agent is a routine practice today. Of these antiinflammatory drugs, steroidal antiinflammatory agents have the disadvantage that although their antiinflammatory activity is high, they are prone to cause immunosuppression as a typical side effect and consequently increased susceptibility to bacterial infection. In any event, the administration of steroidal antiinflammatory agents call for the utmost caution against the risk of bacterial infection.
Under the circumstances the inventors of this invention conducted research on new compounds having both antibacterial and antiinflammatory actions which, if discovered, might solve the above-mentioned problems. In due course, the inventors of this invention succeeded in synthesizing a compound having the structure of an ester between the carboxyl group of a quinolonecarboxylic acid, which is a synthetic antibacterial agent, and the alcoholic hydroxyl group in 21-position of a steroid compound and a pharmacologically acceptable salt thereof and discovered that these compounds meet the above requirements. The findings were followed by further research, which has resulted in the development of this invention.